risky venture vs dangerous undertaking

risky venture and dangerous undertaking both are nouns.

Word	Noun	Adjective	Verb	Adverb
risky venture	Yes	No	No	No
dangerous undertaking	Yes	No	No	No

As nouns, risky venture and dangerous undertaking are synonyms defined as:

risky venture and dangerous undertaking: a wild and exciting undertaking (not necessarily lawful)

Other synonyms of risky venture include adventure, escapade.

risky venture (noun)	dangerous undertaking (noun)
a wild and exciting undertaking (not necessarily lawful)	a wild and exciting undertaking (not necessarily lawful)